Development of Tissue Scaffold of High Strength and Porosity

DESCRIPTION (provided by applicant): According to the Center of Disease Control and Prevention, arthritis is the greatest single cause of chronic pain and disability among Americans .2,3 Currently there is no cure for osteoarthritis, only medication and surgical procedures are available to alleviate the pain and discomfort associated with this degenerative bone disease. Current surgical treatments involve natural and synthetic biomaterials and metal fixation devices. Issues with outcome of biochemical andbiomechanical mismatch in properties between the host bone and implant have created a strong need for a novel biomaterial which mimics the structural properties of bone, while being inherently strong in order to be implanted as a load bearing device. We propose that by using our patented Cross Linked Microstructure(CLM) techniques along with bioactive glass fiber we can engineer a synthetic biomaterial which has an optimized pore structure and high strength at high porosity. The osteoconductive and bioresorable nature of the bioactive glass fiber and our processing technique, would create a high strength scaffold that could be implanted into a patient as load bearing and over time transition into load sharing, as bone grows into the scaffold and the scaffoldmaterial is resorbed into the body. This product incorporates the osteoconductive property of a traditional bone graft the load bearing capability of metal implants and combines it with a biomaterial which is bioresorable, creating a novel implantable device that mimics and regenerates bone without leaving any material in the patient over time. The objective of this proposal is to develop and characterize a tissue scaffold fabricated with bioresorbable osteoconductive glass fibers using our CLM process. The CLM process will be utilized to produce scaffolds with a range of different porosities, pore sizes, mechanical properties and degradation rates. Specific aim 1, is to fabricate bioactive fibers of different diameters to be used in scaffold production. Fibers of various diameters will be used as a controlled variable to alter the characteristics of tissue scaffolds. Specific aim 2, is to fabricate tissue scaffolds using the fiber of various controlled diameters. By controlling the raw material selection and characteristics, we can fabricate scaffolds that have varieties of pore size distribution and porosity. Specific aim 3, is to evaluate the mechanical properties of the fabricated scaffolds. We will determine the porosity, Young's modulus, modulus of rupture, compressive strength, and elastic modulus under compression and compare the resulting values against those of trabecular bone. In specific aim 4, we will perform two phases of testing; in- vitro and in-vivo testing of the material to evaluate its osteoconductive properties and determine its dissolution rate over time. During both phases of testing, samples will be analyzed for bioactivity, sample morphology, and mechanical testing after each incubation or harvest period. Ultimately the outcome of thisproposed feasibility study will lead to a novel biomaterial which may have a broad impact in the future on surgical procedures for the treatment of diseased and damaged bone, which aligns well with the NIH's mission to foster fundamental creative discoveries, innovative research strategies, and their applications as a basis to advance significantly the Nation's capacity to protect and improve health . PUBLIC HEALTH RELEVANCE: Globally, there are an estimated 151 million people who suffer from osteoarthritis. A fifth of these people claim that osteoarthritis hinders them from performing central daily activity.1 Biomaterials are often required in surgical treatments for the replacement or repair of diseased or deteriorated bone tissue to enhance the body's own mechanism to undergo rapid healing of musculoskeletal injuries. We propose that by using our patented Cross Linked Microstructure technique along with bioactive and bioresorable glass in fiber form, we can engineer a novel biomaterial scaffold which has bimodal pore structure, high strength at high porosity and mechanical properties similar to trabecular bone. The resulting high strength scaffold could be implanted into a patient as load bearing device that over time transitions into load sharing as tissue grows into the scaffold and the scaffold material is resorbed into the body, leaving only healthy regenerated bone in its place.